533-73-3Relevant articles and documents
Titanosilicate molecular sieve for size-screening photocatalytic conversion
Shiraishi, Yasuhiro,Saito, Naoya,Hirai, Takayuki
, p. 8304 - 8306 (2005)
Titanosilicate molecular sieves, when activated by ultraviolet light irradiation in water in the presence of molecular oxygen, catalyze a conversion of molecules having a size close to the pore of the catalysts but are inactive for molecules having much larger or smaller size. This unprecedented size-screening photocatalytic activity is triggered by a combination of H2O-induced shortened lifetime of active species (charge-transfer excited state of tetrahedrally coordinated titanium oxide) and restricted diffusion of a molecule inside the pore. This catalytic property demonstrates a potential utility of the catalyst for selective transformation of molecules that is associated with a size reduction of molecules, so-labeled molecular shave transformation. Copyright
Preparation method of sesamol
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, (2021/11/21)
The invention belongs to the technical field of compound synthesis, and particularly relates to a preparation method of sesamol, which firstly prepares 2 -chloro -1, 4 -diphenol, and then 2 - chlorine -1, 4 -biphenol and sodium hydroxide in an aqueous solution to obtain the sesamol, namely 1 2, 1 2 4 - 4 -triphenol and dichloromethane. The invention provides a new method for preparing the sesame phenol, and the yield of the sesamol is remarkably improved.
Antagonistic activity of hydroxycoumarin-based antioxidants as possible singlet oxygen precursor photosensitizers
Guerrero, Tomás,Vázquez-Ortega, Fernanda,Lagunes, Irene,Ortiz-Blanco, Erik,Sosa-Ortiz, Gabriela,Tovar-Miranda, Ricardo,Medina, Manuel E.,Trigos, ángel
, (2021/05/10)
Coumarins are phenolic-type compounds with efficient antioxidant activity due to their ability to scavenge reactive oxygen species. Nevertheless, their ability to behave as photosensitizers capable of generating reactive oxygen species, such as singlet oxygen, has been less studied. In this work, the photosensitizing ability of seven hydroxycoumarins was evaluated through the photooxidation of ergosterol by quantifying the conversion of ergosterol into ergosterol peroxide. In our experimental conditions, we found that almost every tested antioxidant coumarin promotes the peroxidation of ergosterol. The results suggest that the hydroxycoumarins exhibit potential photosensitizing activity by promoting singlet oxygen generation by a Type II photochemical mechanism. Density functional theory (DFT) calculations were also performed to obtain further insight into the chemical reactivity of tested compounds; the observed tendency in the group of antioxidant coumarins to promote the reaction was their hardness due to the principle of maximum hardness. To evaluate our conclusion, we performed the reaction using a highly polarizable coumarin as a photosensitizer, which resulted in an increased photosensitizing capacity supported with DFT calculations, which reinforces our analysis. Finally, we found that hydroxycoumarins can be potentially pro-oxidants since some of them can act as photosensitizers and generate singlet oxygen in the presence of UV–Vis light, a characteristic that must be considered when these compounds are used as antioxidants.
Synthesis of renewable C-C cyclic compounds and high-density biofuels using 5-hydromethylfurfural as a reactant
Cai, Taimei,Deng, Qiang,Deng, Shuguang,Gao, Rui,Peng, Hailong,Wang, Jun,Zeng, Zheling,Zhong, Jin,Zou, Ji-Jun
, p. 2468 - 2473 (2020/05/14)
The major challenge in the synthesis of high-density biofuels is to identify the bio-based source for C-C cyclic compounds and C-C coupling reactions with a suitable selectivity. Herein, we selectively synthesize 1,2,4-benzenetriol (BTO) with a yield of 51.4% from cellulose-derived 5-hydromethylfurfural via a ring-rearrangement reaction. The cellulose-derived route is a more meaningful route for the C-C cyclic compounds compared to the traditional hemicellulose- and lignin-derived routes. Furthermore, BTO is very easily dimerized via a C-C oxidative coupling reaction, showing a yield of 94.4% and selectivity of nearly 100% under environmentally friendly reaction conditions. After hydrodeoxygenation, bicyclohexane is obtained with a yield of 87.4%. This work not only provides a promising route to produce C-C cyclic fine compounds based on a cellulose-derived route, but also shows a highly efficient synthesis route for high-density biofuels via the C-C oxidative coupling reaction.
